John Mather Austin (September 26, 1805-December 20, 1880) was a preeminent Universalist clergyman, editor, author and social activist in New York State, whose most prolific period was the three decades surrounding the Civil War.

The son of Benjamin and Jerusha Mather Austin, he was descended from the New England cleric Increase Mather. He was born in Redfield, New York and grew up in nearby Watertown. It was sometime while he was in his teens that his father converted the family from the Baptist tradition to Universalism. He attended school until the age of 15, when he began lessons in the printing trade. While employed at this trade in the office of the Gospel Anchor in Troy, New York, he joined the Universalist Society there and was inspired by his minister Rev. Clement F. LeFevre to take up studies for the ministry. He preached his first sermon in 1832, received ordination in 1833, and began his first pastorate in Montpelier, Vermont soon afterward. In 1835 he was installed as minister of the church in Peabody, Massachusetts. After nine years he left to accept a call to Auburn, New York and settled there in 1844.

At that time Auburn was a small village in upstate New York, recently hewed out of a wilderness and located in the area of frequent religious revivals that became known as the Burned Over District. In this rather unpromising environment, Austin, while minister of the Auburn congregation substantially increased financial subscriptions and built the second-largest congregation in the village, with over 800 members. He spent much of his free time writing and defending Universalism, both on paper and in controversial debates. His early publications included several guides of conduct, including A Voice to Youth and A Voice to the Married as well as Golden Steps to Respectability. He also wrote a Universalist catechism, The Sabbath School Expositor. By 1848, A Voice to Youth was available in many public school libraries throughout New York.

In 1846 and into 1847 Austin was the only local clergyman to offer public support to William Henry Sewardlater Governor, Senator, and Secretary of Stateduring the highly volatile but ultimately successful Freeman Trial. This case involved racial justice issues and was also one of the earliest cases in the United States to employ the insanity defense. Austin and Seward also collaborated in the local prison reform and anti-slavery organizations, the aftermath of the "Jerry Rescue" civil disobedience event in nearby Syracuse, and possibly even in Underground Railroad efforts. The latter were felony crimes and he never mentioned them directly, even in his diaries, but used only the most opaque references. In his sometimes unpopular stands he was responding from his deepest Universalist beliefs in God as the loving father of all people, and he was fearless in offering his unsolicited support to the criminal Freeman, the escaped slave Jerry, and the lawyer Seward, alike. In return, as long as Seward lived he considered Austin his intimate friend and offered him access to the highest level of political power.

Austin resigned his Auburn pastorate in 1851 to become editor of the weekly Universalist newspaper the Christian Ambassador. He held that position until 1862 when he accepted an offer from President Lincoln for a position as paymaster in the Union army. Seward had recommended him to the President for this post, which carried the rank of Captain. After the war he eventually returned to Auburn, earning a living in secular occupations but he continued to preach part-time to neighboring societies when his health permitted.

Austin married his first wife, Sarah Somerdyke, on October 4, 1828. Of their twelve children only four survived him. He was devastated when Sarah died on August 19, 1855. One year later, on October 8, 1856 he married Eliza Richardson of Auburn. She deserted him after only a few months of marriage but he waited a full decade to secure a divorce because of the stigma attached. After the Civil War, on February 19, 1867, he married the young widow of his deceased army clerk, Mrs. Amelia Bowen, in Fort Wayne, Indiana. They later went to Auburn where he lived with her and her children for the rest of his days.

As editor of the Christian Ambassador, Austin used the power of the press to shape the direction of Universalism in New York State. The largest publication of its kind, it commanded a readership covering the entire state and beyond and its subscribers served as his de facto congregation. Even when his views cost him an occasional supporter he did not hesitate to write in favor of temperance and the Union cause, and against slavery and capital punishment. Together, his publications, social activism, and editorship combined to give him significant influence over Universalism in his day. In the eulogy delivered at Austin's funeral, Rev. Richmond Fiske stated his belief that "the words of ministers of his faith today were more of an echo of, and the faith itself owed more of its firmness and grand comprehensiveness to, the deeds and thoughts of John M. Austin, than to the utterances, by pen or tongue, of any other man, unless it be Dr. [Thomas J.] Sawyer." Austin was laid to rest with his first wife and five of their children in the family plot at Fort Hill Cemetery in Auburn.

A great deal of information can be found in the journals of John Mather Austin, written between 1840 and 1877. The nine volumes of these writings can be found at the Harvard Library. Austin was also a prolific writer of published works. His writings on religious instruction and education include A Voice to Youth, Addressed to Young Men and Young Ladies (1838); A Voice to the Married (1841); A Catechism on the Parables of the New Testament (1842); The source and perpetuity of republicanism: A discourse delivered in Auburn, N. Y., on Sunday evening, October 27, 1844 (1844); and Golden Steps to Respectability, Usefulness and Happiness (1850).

Austin also wrote a great deal in defense of Universalism, taking on the works of numerous challengers. Some of these writings include "Brief Review of William Miller's Destruction of the World," in Otis A. Skinner, The Theory of William Miller, Concerning the End of the World in 1843, Utterly Exploded... (1840); Arguments Drawn from the Attributes of God: In Support of the Doctrine of Universal Salvation (1844); A critical review of a work by Rev. J. S. Backus entitled Universalism, another Gospel, or J.M. Austin vs. the Bible (1849); Review of Rev. A.B. Winfield's book, entitled "Antidote to the errors of universalism," &c (1850); The Sabbath school expositor: Being a compend of the doctrines held by the Universalist denomination (1850); and his compendium volume, A Brief History of Universalism (c. 1855).